Abstract: Low temperature performance of asphalt pavement is one of the main indicator of asphalt pavement design in cold areas, the existing single modified asphalt in low-temperature performance does not meet the requirements of PG technical specifications for asphalt pavement in cold areas. In this project, on the basis of PG test and evaluation results to common road asphalt in low-temperature performance of Heilongjiang province, the composite modified asphalt was researched and developed in order to meet the requirements of low temperature performance of asphalt pavement in cold regions in Heilongjiang province. The research contents include:determination of PG zone and PG_m-n standard of asphalt pavement in Heilongjiang province, PG performance evaluation of road asphalt in Heilongjiang province, research and development and performance evaluation of composite modified asphalt. The research results show that the road asphalt in Heilongjiang province meets the requirements of PG_m-n technology standards in high temperature performance, but does not meet the PG_m-n standards in low temperature performance. The composite modified asphalt meets or nears the PG_m-n standard in low temperature performance of road asphalt in Heilongjiang province. The research results have some theoretical and practical value to improve the low temperature performance of asphalt pavement in Heilongjiang province.